Blood typing is based on the presence of proteins known as on the outer surface of the red blood cell plasma membrane. Blood typing is based on the presence of proteins known as on the outer surface of the red blood cell plasma membrane. A. antibodies B. antigens

Option B) Antigens

Blood typing is based on the presence of proteins known as antigens on the outer surface of the red blood cell plasma membrane.

Explanation:

Blood groups A, B, AB, and O are determined based on the antigen-antibody reactions between donor and recipient bloods.

For instance,

- Blood type A has antigen A on its plasma membrane

- Blood type B has antigen B on its plasma membrane

- Blood type AB has both antigen A and antigen B on its plasma membrane

- while blood type O has neither antigen A nor B on its plasma membrane

So, antigens is the answer

the atmospheric gas that forms a mild acid when dissolved in water is called carbon dioxide. the correct answer is a. 2.) chemical weathering would cause an inscription on a marble headstone to become harder and harder to read over time.